From Banebots, you could buy all the P60 parts individually and assemble the thing yourself. It's about $25 more expensive (Crazy, I know). I can post a list of all the necessary parts for a 20:1 or 26:1 gearbox if anyone's interested.

In my search for gearbox alternatives last year, I came across some possibilities that I've yet to try. WARNING: These look like they interface to an RS-500/550 based on the gearbox drawings. I can't guarantee that, nor do I know anything about the robustness or reliability. Most have the motor attached, so you'll need to press the pinion off the shaft or find a new pinion somewhere.

Ran into the same problem a couple days ago. Those gearbox's are not listed on the FIRST team list of parts. We recalcalculated our need and switched to 775 motors and gearbox's that BB showed available. I would not trust them to get an out of stock order to you in time.

That brings up another possibility. Order a 775 gearbox plus the correct 550 rear block, mounting kit, and pinion. Still more expensive than ordering exactly the gearbox you need, but a little simpler than ordering all the individual pieces.

__________________
The difficult we do today; the impossible we do tomorrow. Miracles by appointment only.

This or a comparable bargain brand drill has approximately the ratio you want and mounts a 550 sized motor. These motor mounts will mount the gearbox. This guide explains how to take apart and modify the drill to lock out the slip clutch.

Based on the relatively low price of the 32DP gears that Robot Marketplace lists, I suspect that we'll be self-building the three ~26:1 gearboxes we need. We had planned on using several the P60 26:1 but learned of the backorder status earlier today (independant confirmation). Sigh.

PLEASE NOTE: We are currently out of material to manufacture 5:1 P60 planet gears. As a result of this all P60 gearboxes with a 5:1 stage will currently be marked out of stock.

We are having more material made; however, it has a lead time putting general availability of 5:1 gears in the late March / early April time frame.

We are continuing to search for alternative sources of material and believe we have found a few small lots. We hope to make a small number (100 - 200) 5:1 and 26:1 P60 gearboxes available within a week. In the interim we encourage you to look at the 4:1, 16:1, 64:1, and 256:1 P60 gearboxes.

I'll bet that modified drill is looking a whole lot better now, huh?

__________________
The difficult we do today; the impossible we do tomorrow. Miracles by appointment only.